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Optimizing LEDs / the dilemma of tall enclosures / tank build log (possibly pic heavy)

Discussion in 'Growing Areas' started by xmpraedicta, Nov 24, 2014.

  1. xmpraedicta

    xmpraedicta Prairie angraecoid nut Supporting Member

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    Hi orchid growing friends,

    Hoping to share a build in progress, as well as pick your brains with some light questions. I'm in the process of figuring out and optimizing a grow cabinet I've had up and running about 5 months now. So far it's been working decently, but has a long way to go. As you can see, only half the tank is operational at this point in time.

    [​IMG]

    [​IMG]

    My struggle right now is optimizing lighting, particularly at the base of the cabinet. I currently light with 3 arrays of 12 x 3W Cree XP-G arrays on heat sinks, no optics, with separately wired fans connected to a computer power supply. It's a horrible nightmare of wires (4 different drivers), but the main issue is insufficient light at the base of the enclosure which is quite tall, 4ft to be exact. I designed it that way to maximize vertical space for pendulous spikes, and I have the plant rack mounted at an angle to capture as much overhead light as possible, but it's not quite enough.

    I've been toying with two different options for a while now, which I tried to illustrate below.
    upload_2014-11-23_23-12-53.png
    The first picture is my current setup. Now I'm trying to figure out is what's more efficient / effective - increasing overall overhead light (image 2), or trying some sort of setup where I mount additional lights at an angle (image 3). I'm leaning towards 3 right now.

    I've tried tall vertical tanks before in the past, using a bank of T5s mounted sideways. It was unsuccessful for other reasons, but I from the light perspective, I think it worked pretty well:

    [​IMG]
    (Lights seen on right)

    I'm mainly posting because those LEDs are deathly expensive, and I've gone through so much DIY hell (aka failures) I was hoping to possibly gather some thoughts before making the leap this time.

    Does anyone have any thoughts on this?
    Experience in lighting tall tanks in order to maximize grow space?
    More on top, or distributing some at an angle?
    And if the angle approach:
    • Thoughts on mounting heavy LED heat sinks + fans?
    • Waterproof LED enclosures? Would something like this work?
    • Would passive cooling be sufficient (e.g. can I do away with the fans) if I go with the newest Cree LEDs?
    Will post updates to this build as I figure things out. Currently working on several components:
    • Light hood - build of two wooden frames, awaiting glass inlays. Currently lights are diffusing through the 6mm polycarbonate, which is very not ideal.
    • Drainage basin - currently water is just dripping down onto the base and evaporating (I have some shamwows to mop up the water). Again, not ideal. Building a wooden drainage basin, and coating it with this stuff, but in retrospect possibly should have tried to get a custom aluminum basin built instead. Oh well! We'll see how it turns out, but hard to get out to the wood shop with -20C outside!
    Thanks in advance for any input!
    [EDIT] Can supply light level readings tomorrow

    -Calvin
     
  2. naoki

    naoki Well-Known Member

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    Calvin, it looks like a very nice enclosure! It looks pretty professional looking.
    A couple comments.

    1. Because of the inverse square law, it is pretty tough to get usable space from tall enclosure.

    From physics of light, if you mount the light source far away, then the difference in the intensity between the top and the bottom of the enclosure is minimized. But it is not practical (you need high ceiling and need narrow beam optics).

    If you can mount the light to the front door (maybe 2 feet from the bottom), then you can have more usable area at the bottom. Or with your image C, you can use narrow beam pattern to target the lighting of the bottom area.

    2. You might want to consider COB-LED for the next addition. It is much easier (maybe < 20 min to make a unit). I didn't have enough DIY skill, so I didn't try DIY LED until COB becomes cheaper. Cree CXA3070 ($40) or Bridgelux Vero 29 ($30) driven at 50W is pretty good. If you want 30W-class, then Vero 18 is much cheaper (around $13-15). I've been using Cree CXA3070, but the lower price of Vero is attractive, so the next addition (I'm ordering them next week) is Vero 29 (which can be driven at 70-100W easily with a small amount of efficiency penalty). The driver for 50W or less is around $13, but above that the driver become expensive (around $30 for cheap 80W or $40-50 for name-brand 80-100W). So 50W is the sweet spot now. I used to think warmer white (3000K) is nicer, but I'm going for the higher absolute light output of 4000K or 5000K next.

    3. Passive cooling is possible, but you need to under drive the LEDs and need fairly big and expensive heatsinks. With active cooling, $10 CPU cooler is enough. Also if you compare 30W active cooled vs 30W passive cooled, active cooled one is "usually" more efficient (more light per watt) even after you consider that the fan consumes extra energy (cooler LED emits more light). So I would recommend going with active cooling. If the noise is the issue, you can try expensive quiet fans.

    4. If you want to optimize the efficiency, did you consider attaching the mylar reflective sheets to the enclosure walls?

    I'm looking forward to seeing how your project progress! It is surprising that there aren't so many orchid people doing DIY LED yet (well, digging through the information at first was pretty tough for me).
     
  3. Natureman

    Natureman Active Member

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    I shouldn't even mention it because I don't know where you can get them, but I have seen LED's mounted to a 24" aluminum heat sink/backer.
    This was just a few months ago at a lighting supplier. These were brighter than a T5 6400k and used less than half the juice; not as hot as T5!
    If anyone knows where you can get them for DIY lights... Let me know!
     
  4. Natureman

    Natureman Active Member

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    Don't know if this viable for you, but one can get a string of outdoor LED's for outdoor(with the gel coating) from China. For under $30US, on can get 16ft of this stuff. If you can find a way to hang it low or just put it on the bottom it might solve your problem!?

    Picture: 16ft of super bright LEDS attached to piece of aluminum screwed in turn to old T5 fixture.
     
  5. Natureman

    Natureman Active Member

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    Forgot pic: ImageUploadedByOrchidsForum.com1416875473.263449.jpg
     
  6. naoki

    naoki Well-Known Member

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    Natureman, are you talking about the LED Strip light? When I looked into it, they were pretty inefficient. Check message #14 in the following forum:

    http://www.candlepowerforums.com/vb/showthread.php?365587-Recent-LED-Strip-Comparisons

    If you are looking for strip-like heatsink for DIY, this place have it:
    http://www.heatsinkusa.com

    If you want to make a long fixture, Bridgelux Vero 10 based project may be the best bang for the buck.

    Some people use 3/4 to 1" aluminum U-channel from HomeDepot as the cheap heat sink (I'm not sure if this is sufficient for Vero 10, though).
     
  7. Ray

    Ray Orchid Iconoclast Supporting Member

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    Be careful about using such lights. They're intended to provide humans with light, not plants.

    White LEDS are very bright because they emit predominantly in the green part of the visible spectrum that the human eye is most sensitive to, not the red and blue ends that plants are.

    I'm not saying they cannot be used for plants, but you're going to want extra wattage to compensate for the spectral imbalance.
     
  8. Natureman

    Natureman Active Member

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    No, I'm not talking 3528 or 5050(that's what I'm showing in my picture, though).
    I'm talking about a brand new 'hard' strip; the LED's are integral to the aluminum plate and they're really bright! Brighter than a 6400 T5. I saw it in a 24" strip. So bright you can't look straight at it....
    Really, my point is that new LEDS are coming soon(if not already here) and the smart money's on holding off until we see this new stuff. I find it very exciting!
    The lighting company I mentioned, had one while I was there buying some repair parts. After I explained I was into orchids, they ordered enough to make a 4' light comparable to a 4' 2 bulb T5... They had me back to show me and it was very impressive... They never called me back with a price, though?
     
  9. xmpraedicta

    xmpraedicta Prairie angraecoid nut Supporting Member

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    Thanks for the replies - much appreciated.

    Naoki - I was hoping for you to reply! I've been playing with the idea of using cobs, and I am seriously considering them, but I have avoided them so far because I've been trying to get away from the spot light effect. However, with the distance, a few of them mounted at strategic points almost like flood lights might be an option. Any thoughts on having these LEDs within the tank and how to create an enclosure that can withstand humidity? I found this:
    [​IMG]
    It's a corner insert heat sink, with a plastic transparent piece. Not sure if the cob will fit inside though...and it would be passive, I think.

    Thanks for the info re the bridgelux cobs. The spectral data looks comparable to the cree, at least with my cursory glance.

    As a logistic question - how do you manage the wires with the separate adaptor for the fan, and the driver for hte LED, once you get a few going, that's lots of wires going everywhere. It would be nice to have a single plug for the LED fixure / fan combo.

    Natureman - I was toying with that idea too, but was under the impression those strips aren't actually too great for growing plants. I went with Cree 3 years ago because I saw proof of incredible growth with setups made by the reef keepers. I have bloomed several things under them since then. Your image seems to show the strips being used to light an orchid growing setup though and I'm willing to try anything - do you have experience with getting plants to grow under these lights?
     

    Attached Files:

  10. naoki

    naoki Well-Known Member

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    Natureman, I wonder what this new stuff you are talking about. It sounds interesting. If you can get more info about this (e.g. who makes it), I'm interested!

    Calvin, you are right; spotlight effect is the disadvantage of big COBs (the lower leaves get shadowed easily)

    My setting is like this. 4x4x8' grow tent with two levels (the top floor is about 4' above the ground). The lower level has 4x 50W COB (but I'm running only 3 at this moment). Since they are inside of a reflective grow tent, the spotlight effect is somewhat buffered. No optics or reflectors are used for each, so it has a wide beam angle. In other words, there are some lights from more distant LEDs reaches to the lower leaves. But I admit that, compared with florescent, there are more shadows. Since you have the skill, bunch of smaller COBs could be better. But I have been focusing on larger COBs, so I don't know which small ones has the best price/performance. I know non-COB Cree XML-2 is pretty good, too.

    My LEDs are inside of the enclosure, and the humidity usually reaches to >90% at night, I don't know how this will influence the longevity of LEDs. I have accidentally splashed water to LED surface a couple times, and it's probably not a good thing. Hopefully, mine doesn't break prematurely... When you look at the data sheet, both bridgelux and Cree mentions that they didn't have failure at 85%RH.

    Waterproofed enclosure would be nice, but I wonder how it will influence the heat management; higher temp means lower efficiency. I haven't investigated about waterproofing, but this one seems to be interesting: LED light engine is sealed for outdoors - Bridgelux. It has Vero 10 with water-resistant enclosure. But it is probably pricey.

    When I put a 30W COB inside of 2x2x3' enclosure, the enclosure became too warm. So, this could be an issue if you put too much LEDs inside.

    Vero 10 is about 2cm diameter. What's the dimension of the triangle heatsink? But you probably need to under-drive quite a bit to use passive cooling with this heatsink (just a guess).

    You are right there are quite a bit of wires (4x driver and 4x 12V for the cooling fan), I just use twist tie etc. in an attempt to organize. I'm using a single 12V AC/DC adapter to drive the four cooling fan, so this does reduce the wire a little bit. I want to keep the enclosure cool, so I have the drivers outside of the enclosure. Then 4x CC drivers + 12V are plugged into a power strip with a switch. It's not pretty, but it works ok for me.

    If you use relatively expensive driver with high voltage, you can connect a few in serial (similar to your XP-G) to reduce the wire. Forward voltage of Vero10 is around 26V for Vero 10, 30V for Vero 13 & 18 , and 40V for Vero 29 and Cree CXA3070. Meanwhile HLG-C series is good for this purpose because it can supply high voltage needed for serial connection.

    http://www.meanwell.com/webnet/search/seriessearch.html
    http://www.meanwell.com/webapp/product/search.aspx?prod=hlg-120h-C
    HLG-120H-C1400 can drive 2x CXA3070/Vero 29 to give 100W total
    HLG-120H-C1050 can drive 3x5 Vero 18 to give 90-150W total
    According to octopart.com (price look-up engine), it costs around $60.

    For V10 with lower current (350mA), you can find much cheaper drivers, e.g. this can drive about 4 Vero 10 to give about 35W.
     
    Last edited: Nov 25, 2014
  11. naoki

    naoki Well-Known Member

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    Ray, we have talked about this (how much light is lost due to the phosphor of white LEDs vs blue and red monochromatic LEDs). I realized that the figure 4 of this paper has some relevant info:

    http://www.plosone.org/article/info:doi/10.1371/journal.pone.0099010

    I would say that cool white isn't so bad (about 20% lower output than blue). This figure doesn't give the complete answer because it doesn't consider that red light is slightly better than blue light for photosynthesis. To consider this point (the wasting energy for green light which you are talking about), we can make a rough calculation with YPF/PPF values from the table 1 of this poster. YPF/PPF is 0.86, 0.7, 0.96 for cool white, blue, and red, respectively. Now if we assign the photon output of Blue as 100%, cool white is about 80%, and red is about 95% (eyeballing from PlosOne figure). So YPF (which is a measurement which incorporate the inefficiency of green light for photosynthesis) would be 0.86 * 0.8 = 0.688 for cool white, 0.7 * 1.0 = 0.7 for blue, and 0.96 * 0.95 = 0.912 for red. So red is the best for photosynthesis, and cool white is about 75% in terms of YPF. I would say that it isn't so bad. Also, I'm not sure how much money company is putting into improving the red LEDs. So if we consider the COB advantage, white LEDs may not be so bad at this moment.

    But there are some issues with this kind of simplistic calculation as you imply (effect of quality of light on biology of plants). But the spectra of LED seems pretty decent compared to the spectra of most florescent light.
     
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  12. MiKa

    MiKa Active Member Supporting Member

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    Naoki -

    I have the same philosofy as you about growth light. And I have used white leds (with good spectrum) for 4-5 years for most of my collection. And I have good results. Just as good and even better than with "extra-fancy-expensive-science-growth-light".

    My good friend Magnus A (on this forum) who is a ph.D. in photosynthesis backs up the same thoughts about white light with a good spectrum as a good alternative.

    ------------------------------------------------------------------------------------------------------------

    To return to the OP's original question I would recommend using PAR38 lamps with 60° lenses to focus light down on the lower parts of your cabinet. This is what they look like:

    [​IMG]

    They can be found in different wattage. 12,15,18W. The one on the picture is 18W with mixed Kelvin diodes (70% 6500K and 30%4500K) The neat thing about these are that you use a standard lamp socket for them and they are not that expensive. I even use them in my greenhouse to reach areas down at he floor.

    _________________________________________________________________________________________

    And when speaking about LED-strip lights.

    Latest technology LED with a crazy light output of 150 lumen/W. 5 mm wide, 3 mm thick. The stick on the picture is 60 cm, 20W and 3000 lumen.
    Mixed diodes of 30% 4500K and 70% 6500K.

    [​IMG]
     
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  13. Natureman

    Natureman Active Member

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    Do you have a pick of that LED stick off? Is it pre wired to the receptacle?
     
  14. naoki

    naoki Well-Known Member

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    Pretty cool, Mikael! Is it a product you are developing or is it available from some company? If the former is the case, you might not want to disclose too much details, but I'm curious what emitters it is using (and driving current). I guess you'll probably need 40x Cree XB-D or XT-E etc driven at pretty low current to achieve 150lm/W (and to allow passive cooling). It seems to be a pretty luxurious design (for low-volume DIY people, it costs at least $40 for the LEDs to get 20W)! One can get similar efficiency (and total of 20W) with 6x XM-L2 or 10x XP-G2 (both would go around $30), but they probably end up with a bigger stick (not as slick looking as yours).

    As a comparison, with Cree CXA3070, you need to get relatively-hard-to-get high-efficiency bin (AB, around $40-50) to achieve that efficiency (after production, they test the LEDs and categorize them into different efficiency "bins", so the same model, e.g. CXA3070 5000K can be available in several flavors of efficiency with slightly different price). Then you have to drive it at a low current (34W). Efficiency (lumen/W, or PAR/W is more relevant to us) increases with lower driving current for any LEDs. But we have to make a compromise, because you need lots of LEDs (which become costly) if you are driving each LED at a low current. This is a part of reason why efficient grow light is more expensive. After setting the lumen/W as a constant (150lm/W), you can get a bit more total lumen per dollar (or euro) with COB. But the strip (or panel) form factor is nicer than the point light source of COB!

    For people who like to waste time in comparing LED data (like me), this cree site is pretty cool:
    http://pct.cree.com/dt/index.html

    I didn't know Magnus's field was in photosynthetic research! It is a very cool field. It is amazing how much (and how little) we know about it. I would expect that companies will be pouring more money to plant optimized LEDs (we have to deal with our growing population size), but the progress seems to be slower than white LEDs.
     
  15. naoki

    naoki Well-Known Member

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    I was just finishing my order of Vero 29, and I noticed this relatively new LEDs.

    http://www.ledsmagazine.com/article...es-board-level-modular-led-light-engines.html

    I haven't checked the details, but I wonder if this is something similar to what Mikael is showing, and what Natureman is talking about. Luxeon XF-3535L seems to achieve 140lm/W to 157lm/W (3000-5000K).

    For example, 4000K, 16.8 W, 525x5.25mm gives 2464lm (147lm/W), and costs $19.37:
    http://www.digikey.com/product-detail/en/L235-4080AMLF5WAD0/1416-1355-1-ND/4966152
    The performance/cost seems to be pretty comparable to COBs from a quick calculation.

    Calvin, this might fit to the triangle heatsink you found (although I don't know the heatsink requirement for this strip light).
     
  16. xmpraedicta

    xmpraedicta Prairie angraecoid nut Supporting Member

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    Thanks for the awesome input. Naoki - you've somewhat of convinced me to go with the mid-higher powered cobs. I saw some neat little heatsink-fan combos on aliexpress (here) that will work well, assuming I can figure a way to mount it on something that can swivel (like this). With a high tank, I think achieving good penetration using optics and angling the light appropriately will be the best solution for me. I'm realizing that a strip light won't provide sufficient light unless I have it close to the plants, even though it will be the least obstructive.

    What I don't understand quite well, however, is CRI vs. Kelvin temperature. I posted this on reddit, but here's what I wrote in case someone can shed some light on this (///GROAN)

    I've been reading online for a while, and still don't quite understand these concepts. According to what I'm reading, CRI is how accurately a light source renders the colours of what it's illuminating, with the sun / thermal radiation from an ideal black body being 100. Colour temperature is how warm/cool the light appears, based upon heating an ideal black body, which will progress with a continuous spectrum of reds, yellows, whites, blues etc... as it is heated. That much I get. I also understand that artificial lights that don't operate by thermal radiation (e.g. fluorescent lights, LEDs) are measured in a correlated colour temperature (CCT), which is just what the eye perceives the light to match, if it were a heated black body.

    What I don't understand is what happens when I compare a cool white vs. a warm white light source, both with CRI of 100? Intuitively I know the colours will be different, and yet why are the CRI the same?

    Is it simply how close the colours will match a source that has a CRI of 100 at a given temperature? E.g. a CFL that has CCT of 2700K and a CRI 90 will match more closely with something illuminated by a heated ideal black body to 2700K, compared to a CFL with CCT of 2700K and CRI of 80. Is this a correct interpretation?

    Secondly, I've noticed that higher CRI LEDs seem to have fewer lumens (e.g. appear dimmer to the naked eye). Is this simply because of the phosphors cutting out the greens / inappropriate wavelengths?

    Mikael - I saw your photos of those strip lights on your flickr and googled the UHOP LEDs and came across dusktropicals. Super interested to see how these work with plant growth. Could be great for smaller vivs.
     
  17. naoki

    naoki Well-Known Member

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    First, the easier Q to answer. For our purpose (grow plants), you should definitely go with the lowest CRI for LEDs (for a given color temp). To achieve higher CRI (flatter emission spectrum), they need to use "more" phosphor (well, this may not an accurate description), so it decreases the efficiency. As you have noticed higher CRI LED has a lower lumen. Similarly, people has calculated PAR from LEDs with different CRI, and lowest CRI for a given color gives the best PAR (almost always). I don't know the answer to the questions about CCT in your 4th&5th paragraph. But simply going with the lowest CRI for a given K is best for us.

    You mentioned phosphors cutting out the green. It is probably similar to what's going on, but I don't think it is a quite accurate description, neither. Phosphors get excited by blue light, and emit reddish light. Somehow they are making the wavelength range of this emitted light wider (I don't know the exact mechanism, here).
    The following doc has a figure to show this (the top figure of p.7):
    Cree XLamp CXA3070 LED Data Sheet - Cree, Inc.
    3000K high CRI has a beautiful, flat emission. 5000K comes in CRI of 70,80,90, but 3000K comes in a bit higher CRI of 80 and 93. I guess 5000K is dominated by blue peaks, so it is more difficult to create higher CRI.

    Choosing the color temp is a bit more complicated. You get more PAR from cool white than warm white. People who grow photoperiodic plants want to have fair amount of red (for flowering), so they prefer 3000K. But many (not all) orchids are NOT photoperiodic. I have both cool and warm white COB, and my orchids seem to grow/flower OK in either one. So similar to Mikael, I went with 5000K and 4000K for the new order to get more absolute PAR (I'll measure and compare the actual PPFD and report it back eventually). Also in several plants, bluer light contributes to more compact plants (the 2nd link in message #15 contains this info), which may or may not be great for orchids.
     
  18. xmpraedicta

    xmpraedicta Prairie angraecoid nut Supporting Member

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    Okay sounds good - I just spent another night wasted reading about phytochromes and understanding exactly how photoperiodicity works. Based upon what I read, I can't really be bothered to fiddle around with light temperatures. However, I might try to adjust length of light between seasons just see what happens.

    Naoki do you offer seasonal temperature fluctuation, and if so, how do you deal with longer than normal winters, being in Alaska? Also, what optics do you use with the vero 29 COB chip?

    Thanks!
     
  19. naoki

    naoki Well-Known Member

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    I decided not to use reflectors. When I was building, I considered getting one of ledil reflector. Here is a link to Vero 29 compatible product:
    http://www.ledil.com/products/?search=true&led=VERO29
    You'll need to calculate what beam angle you'll need. I think you'll likely getting the LEDs from either mouser or digikey, and the last time I checked they didn't have led reflectors in stock. In this case, you can build one without reflector, and see if you need to order a reflector later.

    Learning about phytochrome-mediated photoperiodism is pretty interesting! Another less-understood light sensor is cryptochromes (blue receptors), which influence the shape of plants. I looked up Fundamentals of Orchid Biology by Arditti, and Table 5-29 lists factors that control flowering for a fair number of species(3.5 page, double column table). I used to think most orchids do not show photoperiodism (this seems to be true for most Dens, Phals, Paphs), but there are more photoperiodic orchids than I expected. So there may be a benefit of going to 3000K or 4000K instead of 5000K.

    Yes, it's a bit difficult to give lots of seasonal variation here, but there are about 10F difference between winter and summer. Plants seem to sense the seasonal change (even though the natural light is completely cut-off by the grow tent). But there are some plants which doesn't seem to flower (Phal. wilsonii and its relatives), so I'm experimenting with a larger seasonal changes for some species.

    I forgot to comment on your link to a heatsink. I didn't see the dimension of the area where COB attatches, do you know if it has an appropriate size? Many people use this for Vero 29/CXA3070 class:
    http://www.amazon.com/ARCTIC-Alpine-11-Plus-Cooler/dp/B00606OHQQ/ref=sr_1_1?s=pc&ie=UTF8&qid=1411238141&sr=1-1&keywords=arctic alpine 11
    At this moment the price is pretty high ($17.69), but usually the price is $10. You can set the price tracking option and let camelcamelcamel to email you when the price goes back to the normal price. If you can't wait, this place has it for $12 + some shipping. I use old-left over heatsinks (mostly from old computers, but one is from a Kenmore washing machine).

    Here is a link of a pretty good DIY COB project.
     
  20. xmpraedicta

    xmpraedicta Prairie angraecoid nut Supporting Member

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    Naoki - thank you for being so generous with your knowledge and experience. I've seen that link before and it's a great guide - I'll be following it closely when I assemble my LEDs. I found this on digikey (note - Canadian pricing so much more $$) so that might work too (I think around ~$14 on the US digikey). Surface area is 67mm, and the Vero 29 is 49mm. My question now is how to mount this in the enclosure. Ideally I'd like to be able to swivel it so I can direct the beam. Have you come across anything that enables this? Perhaps the square one you posted is better for that purpose.

    Regarding the reflectors, I have some unfounded feeling they are less effective compared to glass optics for reducing the beam angle, but this is completely not based on evidence, so I'm not sure. I've tried googling for appropriate lenses for the Vero 29, but haven't found anything. I did some calculations and I think a narrow beam angle will help me hit the bottom corners of the tank.

    I am looking a the bins for the Vero and I think I will mix the 5000 with the 3000. You are going with the CRI70 e.g. BXRC-50C10K0-L-04, or the 80 (BXRC-50E10K0-L-04)

    I think the heat will actually be a good thing. It's -25C (-13F) outside, so it's not too difficult keeping my house at around 15C (60F). If the lights can provide that 10-15F diurnal difference, the plants might enjoy it. Right now the day temps are a bit low, and growth is slow. Summer will be a different problem!

    Thanks again...can't wait to get this build started and bring more light to my plants!
     
    Last edited: Nov 28, 2014